The program of research on building materials and structures carried on by the

National Bureau of Standards was undertaken with the assistance of the Central Housing Committee, an informal organization of governmental agencies concerned with

housing construction and finance, which is cooperating in the investigations through a committee of principal technicians.

CENTRAL HOUSING COMMITTEE

ON RESEARCH, DESIGN, AND CONSTRUCTION

Hugh L. Dryden, Chairman. Howard P. Vermilya, Vice Chairman.

National Bureau of Standards. Federal Housing Administration.

Sterling R. March, Secretary.

Mary F, Taylor, Assistant Secretary.

Pierre Blouke, John F. Donovan,

Federal Plome Loan Bank Board. Farm Security Administration.

A. C. Shire, George W. Trayer,

United States Housing Authority. Forest Service (F. P. Laboratory).

Warren G. Noll, Rollo H. Britten,

Public BuUdings Administration. Pubhc Health Service.

LiJTHER M. Leisenring, George E. Knox,

Construction Division (War). Yards and Docks (Navy).

Edward A. Poynton, William R. Talbott,

Office of Indian Affairs. Veterans' Administration.

Wallace Ashby,

Bureau of Agricultural Chemistry and Engineering.

NATIONAL BUREAU OF STANDARDS

STAFF COMMITTEE ON ADMINISTRATION AND COORDINATION

Hugh L. Dryden, Chairman.

Mechanics and Sound.

Phaon H. Bates,

Clay and Silicate Products.

Hobart C. Dickinson,

Heat and Power.

Warren E. Emley,

Organic and Fibrous Materials.

Gustav E. F. Lundell,

Chemistry.

Addams S. McAllister,

Codes and Specifications.

Henry S. Rawdon,

Metallurgy.

The Forest Products Laboratory of the Forest Service is cooperating with both

committees on investigations of wood constructions.

[For list of BMS publications and directions for purchasing, see cover page III.]
UNITED STATES DEPARTMENT OF COMMERCE • Jesse H. Jones, Secretary

NATIONAL BUREAU OF STANDARDS • Lyman J. Briggs, Director

BUILDING MATERIALS

and STRUCTURES

REPORT BMS77

Properties and Performance of Fiber Tile Boards

by

DANIEL A. JESSUP, HERMAN BOGATY

and SAMUEL g. weissberg

ISSUED AUGUST 8, 1941

The National Bureau of Standards is a fact-finding organization;

it does not "approve" any particular material or method of construction. The technical findings in this series of reports are to be construed accordingly.

UNITED STATES GOVERNMENT PRINTING OFFICE • WASHINGTON • I94I

FOR SALE BY THE SUPERINTENDENT OF DOCUMENTS, WASHINGTON, D. C. • PRICE lO CENTS
Foreword

Fiber tile board offers considerable promise as a finishing material

for installations where much more costly materials are ordinarily

used. Samples of this type of board were tested as a part of the

research program on building materials and structures.

Lyman J. Briggs, Director.

[11]
Properties and Performance of Fiber Tile Boards

by DANIEL A. JESSUP, HERMAN BOGATY, and SAMUEL G. WEISSBERG

CONTENTS

Page

Foreword . ii L Introduction 1 IL Description of samples 1 IIL Properties and testing 1 L Thickness and density 2

2. Linear expansion with change in humidity 2

3. Flexura) properties 2

Page

III. Properties and Testing—Continued

4. Thiclvness of coating 3

5. Effect of steam 3

6. Impact tests 4

7. Resistance to abrasion 4

8. Resistance to staining 5 IV. Summary and conclusions 5

ABSTRACT

Performance tests have been made on fiber tile boards by subjecting them to conditions which they might

possibly meet in service. The properties examined

were resistance to abrasive cleaning powders, resistance

to staining by household chemicals, and stability of the boards when subjected to cycles of steaming and drying. In addition, data were obtained on the density, expansivity, and flexural properties of the boards, and on

the thickness and impact resistance of the finish coatings. The resistance of most of the boards to staining, to impact, and to abrasive cleaning powders was good.

Most of the surface coatings were damaged by the

cycles of steaming and drying, especially at the edges,

where moisture had direct access to the base material,

and at the score marks, where the coatings in some of the boards were very thin. The density, expansivity,

and flexural properties were satisfactory.

I. INTRODUCTION

In connection with research at the National

Bureau of Standards on building materials and

structures relative to low-cost housing/ it was

considered desirable to include a study of the

properties of fiber tile boards. Tliis material

is made of vegetable-fiber boards in large

INBS Building Materials and Structures lleport BMSl (1938) lOf!. (See pa^e 3 of cover.

)

sheets, and has on one side a dense, hard coating, either white or colored. The coated siu-- face is frequently scored to resemble the ceramic

wall tile commonly used in more costly struc- tures than those for which the fiber tiles are primarily intended.

II. DESCRIPTION OF SAMPLES

The samples were commercial products furnished by manufacturers. They consisted of

compressed wood-fiber board, coated on one

side with a synthetic plastic. Some of the

coatings were homogeneous, and others had a top layer over a priming coat. Two of the

products had a resinous binding material in the

base boards. There was no added material in the other base boards.

III. PROPERTIES AND TESTING

The samples were tested in their normal

condition for the physical properties commonly

measured on fiberboards, and for resistance to impact, steam, abrasion, and various Hquids

since structural tile in use frequently encounters one or more such deteriorative influences. The

data are contained in tables 1 and 2, respectively.

400301°—41 [1]
Table 1.

Properties of fiber-tile boards

Board Dumber

Thickness Density

Linear

expansion •>

Flexural p

Breaking

load

roperties "

Deflection

at rupture

Coating

thickness <i

IVld- chine Cross Machine Cross Ov r

all Topcoat

in. lb/ft 3 % lb lb in. in. I7i. in. 80 0. 140 69 0. 15 47 50 0. 21 0. 21 (") (") 10 ^

. 145 85 on 79 62 . 15 .15 0. 0070 0. 0070

11 . 140 83 . 15 91 74 .15 .15 .0152 .0026

20 . 160 76 . 10 96 80 . 10 .06 . 0120 . 0022

30 . 133 65 . 19 42 44 . 22 . 27 .0028 . 0012

40 .144 72 .10 50 53 .21 .23 .0048 .0048

50 . 146 73 . lo 56 50 .18 .20 .0036 .0036

51 . 141 71 . 13 51 58 .18 .17 .0064 .0060

52 . 143 70 . 10 55 66 .18 .20 .0071 .0066

70 . 140 71 . 15 48 51 .20 .19 .0036 .0036

onyu 148 69 17 56 51 .16 .17 .0042 .0018

91 !l48 69 !20 50 53 .13 .15 .0054 .0038 100__- .142 70 .25 47 52 .17 .18 .0028 .0028 no._- .136 73 .17 50 44 .20 .19 .0044 .0020 111... .140 70 .16 52 48 .19 .19 .0062 .0028

130- .150 67 .15 55 55 .18 .17 .0062 .0062 131.-- . 150 67 .17 57 55 .20 .19 .0036 .0036 140--- .139 73 .17 56 57 .20 .18 .0042 .0018 141--. . 139 73 .14 62 65 . 16 .17 .0066 .0066

o Samples 10 and 11 are compressed wood fiber with a resinous binder. The remainder of the boards are compressed wood fiber with no added

material. Sample 80 has no surface coat and is included for comparison.

b For a change in relative humidity of surrounding atmosphere from

EO to 95 percent. For specimens 1 inch wide on supports 3 inches apart.

J Identical figures for over-all thickness and topcoat thickness indicate aboard with a single coat. Table 2.

Resistance of fiber tile boards to deteriorative influences

Board

number

Resistance to impact » Resistance to steam Resistance to abrasion

Before steamingAfter steaming

Extent

of

warping

^

Color

Gloss

Blistering

of

surface

Entire

coating

<i

Per

0.001

inch

of

coating

1-oz

weight

2-oz

weight

1-oz

weight

2-oz

weight

Tliniis. Thous.

of of

in. in. in. in. in. cycles cycles

lOe..- 30 7 U 11 0.400 Good... Poor B 75 10.7 II--- 29 8 39 8 1.12 Poor ---do-— B 60 3.9 20«-. 40 34 40 31 . 172 Fair.... --.do- — None 60 5.0 30—- 13 5 39 14 . 135 Good... Good--- E. 8 15 5.4

40-... 20 8 29 9 .063 ...do...- ...dc... E, B 40 8.3 SO—

18 8 19 4 .126 ...do— Poor s, L 15 4. 2 61—- 23 6 20 5 .004 .-do.-.- ...do.... E 53 8.3

52-.-. 18 7 11 2 .048 ---do.... ...do— S, L 40 5.6 70.-- 7 4 8 4 .035 --.do— ..-do.... B, E 20 5. 6 90..- 6 4 9 4 .020 --do— Good... B, E 15 3. 6 91.— 7 4 7 4 .045 ---do—

...do.... B, E 15 2.8 100-- 13 3 20 9 .0")1 Poor Fair B, 8 4 1.4 110-- 14 10 34 12 .033 --.do- — ...do-... B, S 20 4. 5 111— 16 5 29 10 .050 Good... Good... B, E 15 2.4 130-- 8 7 24 14 .040 --.do—

Poor 8 6 1.0 131-- 10 6 25 14 .040 .-.do.... .--do.— E 17 4, 7 140-.. 10 6 34 14 .022 Poor --_do--- B, E 8 1.9

141--. 6 3 15 4 .007 Good-- Fair--_ B. E 24 3.6

» Impact tests were made by dropping a cylindrical weight on the

surfaces of the boards placed at 30° to the horizontal. The values recorded

are the shortest distances required to break the surface.

b Measured at the center of a 12-inch span.

c The letters indicate the places where the blistering effect was noted: B=on broken surfaces, iS=at edges of the board, S=at score marks, i=loosening of the coating.

d Number of thousands of cycles of scrubbing with a cloth pad, soap and water, and mild household cleanser to wear coating through to base

material.

e Samples 10, 11, and 20 were not stained by writing ink, 5 percent

acetic acid, tincture of iodine, or hot grease. The remaining samples

were stained only by 5 percent acetic acid and by commercial tincture

of iodine. 'Samples 10, 40, 50, 51, 52, 70,90, 91,130, 131, and Hlhad whitesurfaces; samples 30, 50, 51, 52, 70, 91, 100, 110, and 130 were scored to resemble

ceramic tile.

1. Thickness and Density

The density of the tile board is the weight

per unit of volume. It was computed from

measurements of dimensions and from determination of weight. In most cases specimens

about 18 by 18 inches were used. The weight was determined on a torsion balance reading

to 0.1 gram, and the thickness was determined

by means of a micrometer caliper reading to 0.001 inch.

2. Linear Expansion With Change in

Humidity

The change in dimensions with a change in

the relative humidity of the surrounding atmosphere is an important characteristic of interior

finishing materials. Low expansivity minimizes the difficulties encountered with waving,

budding, and opening of seams when extreme

humidity conditions occur. The linear-expansion tests were made in accordance with the Federal Specification for

fiber insulating board.^ Test specimens

measuring about 12 by 2 inches were conditioned

in an atmosphere at 50-percentralative humidity

and then conditioned for 48 hours in an atmosphere at 95-percent relative humidity. The

changes of length were determined from the

displacement of reference marks placed about

8 inches apart on the specimen.

3. Flexural Properties

Although tile boards are not generally

required to contribute to the strength of a

structure, the boards must be of sufficient

strength to withstand, without undue breakage,

handling incidental to installation, and to resist damage after installation. The strength of

fiber building boards is generally determined

in terms of flexural properties. These were

determined by placing a specimen 1 inch wide

across two parallel supports 3 inches apart and

loading at the midspan. The load is conveniently applied by means of a tensile testing

machine with suitable fixtures. The rupturing

load and the deflection at instant of rupture

are recorded. This method is one developed

at the Bureau for use with binders board.

» Federal Specification LLL-F-321a Fiber Boards; Insulating.

3 Paper Trade J. 95, No. 16, 183 (Oct. 20, 1932).

[2]
4. Thickness of Coating

The thickness of the coating was determined

by an adaptation of Mesle's chord method.

This method has been used successfully for

the measurement of the thickness of plated

metal coatings.^

A precision grinding wheel of luiown radius,

B, is lowered upon the surface of the tile board

with the axis of the wheel parallel to the plane

of the board, as illustrated in figure 1. The

FlGtTBE 1.-

RelaU'onsmp between radius of grinding wheel and thickness of coat. A, surface coat; B, base material.

surface of thickness, T, is ground tlu-ough until

the wheel reaches the base material along a

line through P. The width of the cut, C, is related to the thickness, T, and the radius of the

grinder, R, as follows: R'={R-Tr+(^' or 2RT^r+^-

As Tis about 0.01 inch, R about 4 inches, and

C about 0.5 inch, may be neglected, making

T={Cy8R).

In practice the plane of the specimen is tilted so that it makes an angle of about 1° with the

axis of the wheel. This gives a cut with a

semielliptical plan (fig. 2). TUting has the

advantage that, when there is more than one

layer of coating, aU are exposed for measure- ment with but one grinding operation. Moreover, there is no uncertainty as to the endpoint

of the grinding operation. The width of the

cut, C, for a particular coating is measured at

the apex of the ellipse formed by the intersection of the wheel with the plane separating the

coating under consideration from the next lower

layer.

*J. Research NBS 16, 171 (1936) RP866.

5. Effect of Steam

A test was devised whereby the surface of

the fiber tile was exposed to the action of con- densing steam for 7 hours and then allowed to dry for 17 hom-s. Changes in appearance and

properties were determined after five sucli cycles of steaming and drying. The changes

produced in some of the boards as a result of

this treatment are shown in figures 3, 4, and 5. Warping was determined by means of a cylindrometer. This device consists of two rigid

feet fixed 12 inches apart and a movable foot

attached to a dial micrometer at the center of

the span. A zero reading is obtained by holding

the instrument on a plate-glass surface. The

difference between the micrometer reading on

the warped board and tlie zero reading gives

the degree of warping.

The warping was extreme in only two of the

samples. The base material of these was compressed wood fiber with a resinous binder.

The resistance of the coating to change of

gloss and color after steaming was rated as

Figure 2.Appearance of the cut on the surface of the

fiber tile board. A, surface coatings; D, base material; C, exposed top coat; D, exposed under coat; E, exposed base material; F, grinding wheel. follows: Good, no change; fair, slight but not

objectionable; poor, considerable change.

Most of the boards became less glossy on

steaming and many of the colored boards faded

(fig. 3). In general the color of the white

boards was unaffected by steam.

The coatings of most of the boards underwent some surface change. Steaming caused wheals

or bhsters to form, generally at tne edges, near

score marks, or at places where the coatiag had

[3]
Figure 3.-

Color change -produced by steaming.

Unexposed portion is so marked

been scratched or broken (fig. 4). In two

instances the coating loosened, and tended to separate from the base (fig. 5).

6. Impact Tests

Impact tests on the coated surfaces of tile boards were used as a measure of the resistance

to chipping by hard blows. Specimens were

placed in a metal frame at an angle of 30° with

the horizontal, to simulate glancing blows, and

weights were allowed to fall on the surfaces.

The shortest distance of fall required to break

the surface was recorded. The weights were hardened steel cylinders, inch in diameter,

with the edges rounded to a radius of 0.025

inch. The cylinder axis at the moment of impact was vertical. Tests were ma de with 1- and

2-ounce weights on both the original and the

steam-treated boards.

The surface in most cases showed no deterioration after steaming with respect to resistance

to impact. The coatings in many rristances

appeared to be toughened by steaming.

7. Resistance to Abrasion

The surface was tested for resistance to abrasion by mechanically scrubbing it with v clothfaced pad moving with a reciprocating motion.

A device was constructed whereby a number of

specimens could be tested simidtaneously. The

scrubbing pads were composed of wood blocks

2}i inches square covered with a piece of wool

blanket over wliich was fastened a piece of

sturdy twill cloth. A load of 1% pounds was

applied to the pads. The stroke of the pads was 4 inches, and the rete of scrubbing was

2,500 cycles per hour. The specimens, fixed in

pla.ce beneath the moving pads, were moistened

from time to time with a 1 -percent soap solution

[4]
to which a mild household cleaning powder had

been added.

Change in gloss could not be used as a measure of resistance to abrasion, because the polishiag effect of the scrubbing prevented change of

gloss. The best indication of resistance to abrasion appeared to be the number of cycles

necessary to cause the coat to wear completely

through to the base. Tliis criterion was used

since, ia practice, the board tiles might not have

to be replaced mitil this occurred. As might

be expected, there is a fairly good correlation

between the resistance to abrasion and the overall thiclcness of the coat.

8. Resistance to Staining

The resistance of the coating to staining by

common household materials was tested by

placing milliliter of the following liquids on

the surfaces: a 5-percent solution of washing

soda, 5-percent solution of acetic acid, commercial tincture of iodine, commercial writing uik,

hot bacon grease. The drop was allowed to stand for hour and then wiped with a clean

cloth, using soap and water, if necessaiy, for thorough cleaning. Most of the boards were stamed by dilute acid and iodine. The other

compounds had no appreciable effect on the

coatings.

IV. SUMMARY AND CONCLUSIONS

The tests of the fiber tile boards studied

showed that they are very dense, have a moderate degree of expansion with change in

moisture content, and are strong and rigid.

The thickness of the coating varies considerably.

The resistance of the coatings of the boards

to abrasion was excellent, particularly for those

having double coatings.

Steam did not adversely affect the resistance

Figure 4.

Blistering at score marks, caused by swelliny of base material when subjected to steam.

[S]
Figure 5.

Loosening of surface coat due to failure of bond bdiveen surface coat and base material when siearned.

of the coatings to impact, but the gloss of most

of the coatings was dulled and the colored ones

faded. The steaming in general did not affect the color of the white coatings. All coatings

treated with steam were blistered, this generally occurring at the edges of the board, near

score marks, or where the coatuig had been

scratched. Steam produced excessive warping

of two of the boards. The coatmgs were

resistant to staining by writing ink and hot

grease, but most of them were stained by weak

acetic acid and by tincture of iodine.

Washington, May 20. 1941.

[6]
BUILDING MATERIALS AND STRUCTURES REPORTS

On request, the Superintendent of Documents, U. S. Government Printing Office, Washington, D. C, will place your name on a special mailing list to receive notices of new reports in this

series as soon as they are issued. There will be no charge for receiving such notices. An alternative method is to deposit with the Superintendent of Documents the sum of $5, with the request that the reports be sent to you as soon as issued, and that the cost thereof be

charged against your deposit. This will provide for the maiUng of the pubUcations without

delay. You will be notified when the amount of your deposit has become exhausted.

If 100 copies or more of any report are ordered at one time, a discount of 25 percent is allowed. Send all orders and remittances to the Superintendent of Documents, U. S. Government Printing

Office, Washington, D. C.

The following publications in this series are available by purchase from the Superintendent of Documents at the prices indicated:

BMSl Research on Building Materials and Structures for Use in Low-Cost Housing 10(6 BMS2 Methods of Determining the Structural Properties of Low-Cost House Constructions 10^ BMS3 Suitability of Fiber Insulating Lath as a Plaster Base 10^ BMS4 Accelerated Aging of Fiber Building Boards 100 BMS5 Structural Properties of Six Masonry Wall Constructions 15^ BMS6 Survey of Roofing Materials in the Southeastern States 15^ BMS7 Water PermeabUity of Masonry Walls 100 BMS8 Methods of Investigation of Surface Treatment for Corrosion Protection of Steel 100 BMS9 Structural Properties of the Insulated Steel Construction Co.'s "Frameless-Steel" Constructions for Walls, Partitions, Floors, and Roofs 100 BMSIO Structural Properties of One of the "Keystone Beam Steel Floor" Constructions Sponsored by the H. H. Robertson Co 100 BMSll Structural Properties of the Curren Fabrihome Corporation's "Fabrihome" Constructions for Walls and Partitions 100 BMS12 Structural Properties of "Steelox" Constructions for Walls, Partitions, Floors, and Roofs

Sponsored by Steel Buildings, Inc 150 BMS13 Properties of Some Fiber Building Boards of Current Manufacture 100 BMS14 Indentation and Recovery of Low-Cost Floor Coverings 100 BMS15 Structural Properties of "Wheeling Long-Span Steel Floor" Construction Sponsored by

the Wheeling Corrugating Co 100 BMS16 Structural Properties of a "Tilecrete" Floor Construction Sponsored by Tilecrete Floors, Inc 100 BMS17 Sound Insulation of Wall and Floor Constructions 100 BMS18 Structural Properties of "Pre-Fab" Constructions for Walls, Partitions, and Floors Sponsored by the Harnischfeger Corporation 100 BMS19 Preparation and Revision of Building Codes 150 BMS20 Structural Properties of "Twachtman" Constructions for Walls and Floors Sponsored by

Connecticut Pre-Cast Buildings Corporation 100 BMS21 Structural Properties of a Concrete-Block Cavity-Wall Construction Sponsored by the National Concrete Masonry Association 100 BMS22 Structural Properties of "Dun-Ti-Stone" WaU Construction Sponsored by the W. E. Dunn Manufacturing Co 100 BMS23 Structural Properties of a Brick Cavity-Wall Construction Sponsored by the Brick

Manufacturers Association of New York, Inc 100 BMS24 Structural Properties of a Reinforced-Brick Wall Construction and a Brick-Tile CavityWall Construction Sponsored by the Structural Clay Products Institute 100 BMS25 Structural Properties of Conventional Wood-Frame Constructions for Walls, Partitions,

Floors, and Roofs 150 BMS26 Structural Properties of "Nelson Pre-Cast Concrete Foundation" WaU Construction

Sponsored by the Nelson Cement Stone Co., Inc 100 BMS27 Structural Properties of "Bender Steel Home" WaU Construction Sponsored by The

Bender Body Co 100 BMS28 Backflow Prevention in Over-Rim Water Supplies 100 BMS29 Survey of Roofing Materials in the Northeastern States 100 BMS30 Structural Properties of a Wood-Frame WaU Construction Sponsored by the Douglas

Fir Plywood Association 100 BMS31 Structural Properties of "Insulite" WaU and "Insulite" Partition Constructions Sponsored by The Insulite Co 150 BMS32 Structural Properties of Two Brick-Concrete-Block Wall Constructions and a Concrete- Block Wall Construction Sponsored by the National Concrete Masonry Association. 10^

[List continued on cover page IV]
BUILDING MATERIALS AND STRUCTURES REPORTS

[Continued from cover page III] BMS33 Plastic Calking Materials 10(4 BMS34 Performance Test of Floor Coverings for Use in Low-Cost Housing: Part 1 10(4 BMS35 Stability of Sheathing Papers as Determined by Accelerated Aging 10^ BMS36 Structural Properties of Wood-Frame WaU, Partition, Floor, and Roof Constructions

With "Red Stripe" Lath Sponsored by The Weston Paper and Manufacturing Co.. 10(4 BMS37 Structural Properties of "Palisade Homes" Constructions for Walls, Partitions, and

Floors, Sponsored by Palisade Homes 10j4 BMS38 Structural Properties of Two "Dunstone" Wall Constructions Sponsored by the W. E. Dunn Manufacturing Co 10(4 BMS39 Structural Properties of a Wall Construction of "Pfeifer Units" Sponsored by the Wisconsin Units Co 10^ BMS40 Structural Properties of a Wall Construction of "Knap Concrete WaU Units" Sponsored

by Knap America, Inc 10^ BMS41 Effect of Heating and Cooling on the Permeability of Masonry Walls lOjS BMS42 Structural Properties of Wood-Frame Wall and Partition Constructions With "Celotex"

Insulating Boards Sponsored by The Celotex Corporation lOjS BMS43 Performance Test of Floor Coverings for Use in Low-Cost Housing: Part 2 10^ BMS44 Surface Treatment of Steel Prior to Painting 10^ BMS45 Air Infiltration Through Windows 10^ BMS46 Structural Properties of "Scot-Bilt" Prefabricated Sheet-Steel Constructions for Walls,

Floors, and Roofs Sponsored by The Globe-Wernicke Co 10(4 BMS47 Structural Properties of Prefabricated Wood-Frame Constructions for Walls, Partitions,

and Floors Sponsored by American Houses, Inc 10(4 BMS48 Structural Properties of "Precision-Built" Frame Wall and Partition Constructions

Sponsored by the Homasote Co 10(4 BMS49 Metallic Roofing for Low-Cost House Construction „ 10(4 BMS50 Stability of Fiber Building Boards as Determined by Accelerated Aging 10(4 BMS51 Structural Properties of "Tilecrete Type A" Floor Construction Sponsored by the Tile- crete Corporation 10<^ BMS52 Effect of Ceiling Insulation on Summer Comfort 100 BMS53 Structural Properties of a Masonry WaU Construction of "Munlock Dry WaU Brick"

Sponsored by the Munlock Engineering Co 10(4 BMS54 Effect of Soot on the Rating of an Oil-Fired Heating Boiler 10^ BMS55 Effects of Wetting and Drying on the Permeability of Masonry WaUs 10(4 BMS56 A Survey of Humidities in Residences 10^ BMS57 Roofing in the United States: Results of a Questionnaire 10{5

BMS58 Strength of Soft-Soldered Joints in Copper Tubing 10(4 BMS59 Properties of Adhesives for Floor Coverings 100 BMS60 Strength, Absorption, and Resistance to Laboratory Freezing and Thawing of Building

Bricks Produced in the United States 150 BMS61 Structural Properties of Two Nonreinforced Monolithic Concrete Wall Constructions 100 BMS62 Structural Properties of a Precast Joist Concrete Floor Construction Sponsored by the Portland Cement Association 100 BMS63 Moisture Condensation in Building WaUs 100 BMS64 Solar Heating of Various Surfaces 100 BMS65 Methods of Estimating Loads in Plumbing Systems 100 BMS66 Plumbing Manual 200 BMS67 Structural Properties of "Mu-Steel" Prefabricated Sheet-Steel Constructions for Walls,

Partitions, Floors, and Roofs Sponsored by Herman A. Mugler 150 BMS68 Performance Test of Floor Coverings for Use in Low-Cost Housing: Part 3 150 BMS69 Stability of Fiber Sheathing Boards as Determined by Accelerated Aging 100 BMS70 Asphalt-Prepared Roll Roofings and Shingles 150 BMS71 Fire Tests of Wood- and Metal-Framed Partitions 100 BMS72 Structural Properties of "Precision-Built, Jr." Prefabricated Vfood-Frame WaU Construction Sponsored by the Homasote Co 100 BMS73 Indentation Characteristics of Floor Coverings 100 BMS74 Structural and Heat-Transfer Properties of "U. S. S. Panelbilt" Prefabricated Sheet-Steel Constructions for Walls, Partitions, and Roofs Sponsored by the Tennessee Coal, Iron & Railroad Co 100 BMS75 Survey of Roofing Materials in the North Central States 150 BMS77 Properties and Performance of Fiber Tile Boards 100